Inductively chargeable audio devices

ABSTRACT

An inductively enabled audio speaker is disclosed configured to receive power inductively from an inductive power outlet. The audio speaker device has a voice coil which, as well as being able to produce an audible output, is further configured to function as a secondary inductor to inductively couple with a primary inductor. The inductively enabled audio speaker may be used to power an electrical device such as a Bluetooth earpiece, a telephone or the like.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to patent application Ser. No.12/693,001, filed Jan. 25, 2010, which is a continuation of PCTapplication Serial No. PCT/IL2008/001348 filed Oct. 12, 2008, whichclaims the benefit of U.S. provisional application Ser. Nos. 60/960,635filed Oct. 9, 2007; 60/960,878 filed Oct. 18, 2007; 61/006,131 filedDec. 26, 2007 and 61/064,403 filed Mar. 4, 2008, which are herebyincorporated by reference in their entirety.

FIELD OF THE INVENTION

The present invention is directed to providing power to electricaldevices. In particular the present invention relates to portableelectrical devices adapted to receive power inductively.

BACKGROUND

Mobile communication devices, such as computers, cellular telephones andthe like, are typically powered by power cells, i.e. rechargeableelectrochemical cells often also referred to as batteries. In order torecharge the power cells such devices are generally provided with acharger unit for connecting to a power jack socket on the device whichis wired to contacts with the terminals of the cells. The charger itselfusually consists of a plug box containing a step-down transformer and anAC-DC converter or rectifier which is wired to a connecting plug. Whenin use, the plug box is plugged into a 120V or 240V mains socket and theconnecting plug is coupled to the device. The wire trailing between thedevice and the plug box can be unsightly. Moreover, if the trailing wireis snagged or jerked the wire and connectors may be damaged, as indeedcould be the socket or the wall. Furthermore, the device may be pulledto the ground.

Chargers are bulky items to carry around. Therefore most users ofcompact portable equipment such as cell phones and the like do not carrychargers with them, but prefer to rely upon periodic charging, perhapsover night. Often users rely on even more infrequent charging. As aresult cells often run down at inconvenient times when no charger isavailable.

Inductive battery charger systems are known such as the system describedin U.S. Pat. No. 7,164,255 to Hui incorporated herein by reference. InHui's system a planar inductive battery charging system is designed toenable electronic devices to be recharged. The system includes a planarcharging module having a charging surface on which a device to berecharged is placed. Within the charging module, and parallel to thecharging surface, is at least one, and preferably an array of primarywindings that couple energy inductively to a secondary winding withinthe device to be recharged. The invention also provides secondarymodules that allow the system to be used with conventional electronicdevices not formed with secondary windings.

Hui's system provides an inductive charging platform for mobiletelephones. However, unless the device to be charged has an integralsecondary winding coil, it is necessary to carry a bulky secondarymodule with which to use the platform. Hui' s system does not describeany convenient means for providing secondary windings for conventionaldevices.

There is therefore a need for a convenient power supply for a mobilecommunication device and particularly for a charger, which may beconveniently retrofitted to conventional devices.

SUMMARY

It is an aim of the invention to provide an inductive power providingsystem for an electrical device.

In accordance with a first embodiment, the present invention is directedto providing a power providing system for an electrical devicecomprising: a secondary inductor, wired to the electrical device, forinductively coupling with a primary inductor hardwired to a powersupply, wherein the secondary inductor is incorporated into an accessoryof the electrical device.

In various embodiments the electrical device may be selected from thegroup comprising: computers, mobile telephones, media players, PDAs,Walkman®s, portable CD players, dictaphones, portable DVD players andmobile communications devices. The accessory may be selected from thegroup comprising: removable casings of the electrical device, carryingcases for transporting the electrical device, straps for carrying theelectrical device, carrying handles, fashion-tags, ornamental pendants,mobile danglers, skins for encasing the electrical device, stickers foradhering to the electrical device, belt-clips, neck support straps andearphone units.

Optionally, the secondary inductor comprises an electrical connector forcoupling to a power jack socket such that the secondary inductor isretrofittable to the electrical device. Preferably, the electricalconnector comprises a hermaphrodite connector comprising: a male plugportion, for coupling with the power jack socket and a female socketportion for coupling to an external power source.

In some embodiments the electrical device comprises a removable powerpack; the power pack being connectable to the electrical device viacontacts, the secondary inductor comprising an electrical connector forcoupling to the contacts. Preferably, the electrical device furthercomprises an electrochemical cell, and the secondary inductor isconnected to the electrochemical cell via a rectifier for charging theelectrochemical cell.

Optionally, the accessory comprises a USB plug for coupling to acomputer such that the electrochemical cell is selectably chargeable bypower drawn from the computer. Typically, the USB plug is wired to adata jack socket of the electrical device such that data is exchangeablebetween the computer and the mobile communication device.

In preferred embodiments, the power providing system further comprisesan audio device having an external earphone unit, wherein the secondaryinductor is incorporated into the earphone unit. Typically, the externalearphone unit, comprises at least one inductive element for inductivelycoupling the primary inductor to the secondary inductor. Optionally, thethe inductive element comprising the secondary inductor. The secondaryinductor may comprise a voice coil of at least one speaker of theearphone unit. Alternatively, the secondary inductor comprises at leastone loop of wire. The loop of wire may be incorporated into a necksupport strap for supporting the audio device. Alternatively, the endsof at least one wire are connected together to produce the at least oneloop of wire. In other embodiments of the invention the earphone unitincludes an inductive element which comprises a ferromagnetic coreextending through the secondary inductor and into the earphone unit forselectively coupling with the primary inductor.

In still another embodiment of the invention, the power providing systemcomprises at least one inductive coil, the inductive coil beingselectively connectable to: at least one charging circuit for connectingthe inductive coil to a power pack via a rectifier for charging thepower pack when the secondary inductor is inductively coupled to theprimary inductor; and at least one driving circuit connectable to thepower pack for providing a varying electrical potential to the inductivecoil such that the inductive coil transfers power to an externalinductor wired to an external electrical load. Preferably, the powerpack is selected from the group comprising: nickel-cadmium cells, nickelmetal hydride cells, alkaline cells, flow batteries, rechargeableelectrochemical cells and capacitors. Optionally, the power providingsystem comprising a ferromagnetic core for guiding magnetic flux throughthe inductive coil when inductively coupled. Typically, the drivercomprises at least one switching unit for intermittently connecting thepower pack to the inductive coil at high frequency.

Optionally, the power providing system additionally comprises a jack forconductively connecting the power pack to an external power source forcharging purposes. The power providing system may additionally comprisea jack for conductively connecting the power pack to the externalelectrical load.

It is a further aim of the invention to provide a computer comprising aninductive coil which is selectively connectable to: at least onecharging circuit for connecting the inductive coil to a power pack via arectifier for charging the power pack when the secondary inductor isinductively coupled to the primary inductor; and at least one drivingcircuit connectable to the power pack for providing a varying electricalpotential to the inductive coil such that the inductive coil transferspower to an external inductor wired to an external electrical load.Preferably, the power pack is configured to power the computer.

It is a further aim of the invention to provide an inductive chargercomprising at least one inductive coil and at least one chargeable powerpack, the charger additionally comprising: at least one charging circuitfor connecting the inductive coil to the power pack when the inductivecoil is inductively coupled to a primary coil wired to a power supplyfor charging the power pack; and at least one driving circuitconnectable to the power pack for providing a varying electricalpotential to the inductive coil such that the inductive coil isinductively couplable to a secondary coil wired to an electrical load.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the invention and to show how it may becarried into effect, reference will now be made, purely by way ofexample, to the accompanying drawings.

With specific reference now to the drawings in detail, it is stressedthat the particulars shown are by way of example and for purposes ofillustrative discussion of the preferred embodiments of the presentinvention only, and are presented in the cause of providing what isbelieved to be the most useful and readily understood description of theprinciples and conceptual aspects of the invention. In this regard, noattempt is made to show structural details of the invention in moredetail than is necessary for a fundamental understanding of theinvention; the description taken with the drawings making apparent tothose skilled in the art how the several forms of the invention may beembodied in practice. In the accompanying drawings:

FIG. 1 is a schematic illustration of an inductive power providing meansfor powering a computer, in accordance with one embodiment of thepresent invention;

FIG. 2 is a schematic illustration of a computer provided with asecondary inductive coil incorporated within the base thereof, forinductively powering the computer by bringing into proximity with apower supplying inductive coil, according to another embodiment of theinvention;

FIG. 3 shows the jack sockets of a portable computer according to afurther embodiment of the invention for coupling to an electricity mainspower source via an inductive couple or via a conventional power supply;

FIG. 4 is a schematic illustration of a computer carrying case accordingto another embodiment of the invention with an inductive power coilbuilt into the base thereof;

FIG. 5 is a schematic illustration of another embodiment of the computercarrying case having an inductive power coil built into the handlethereof;

FIG. 6 is a schematic illustration of still another embodiment of thecomputer carrying case having an inductive power coil built into theshoulder strap thereof;

FIGS. 7 a and 7 b are schematic illustrations of a retrofittablecarrying handle for a portable computer with a built-in inductive powercoil according to further embodiments of the invention;

FIG. 8 is a schematic illustration of a fashion-tag attachment with abuilt-in inductive power coil in accordance with still anotherembodiment of the invention;

FIGS. 9 a and 9 b are schematic illustrations of a computer providedwith another embodiment of the invention including a retractablesecondary inductive coil attachment;

FIG. 10 is a schematic illustration of an inductive charger for a mobilecommunication device of a further embodiment of the invention;

FIGS. 11 a and 11 b are schematic illustrations of a mobilecommunication device with an inductive charger built into the skinthereof according to another embodiment of the invention;

FIG. 12 a is a schematic illustration of a self-adhesive inductivecharger for a mobile communication device adhered to a power cellaccording to another embodiment of the invention;

FIG. 12 b is a schematic illustration of how the self-adhesive inductivecharger of FIG. 12 a may be used to charge cells;

FIG. 13 is a schematic illustration of an inductive charger of anotherembodiment of the invention having a hermaphrodite power connector;

FIGS. 14 a-c are schematic illustrations of a protective case accordingto a further embodiment of the invention with a built-in an inductivecharger for a mobile communication device;

FIG. 15 is a schematic illustration of a mobile communication devicewith an inductive charger built into a fashion tag;

FIG. 16 is a schematic illustration of an inductive charger for a mobilecommunication device with a combined data connector;

FIG. 17 is a block diagram showing the main elements of a charger for anaudio device incorporated into an earphone unit in accordance withanother embodiment of the invention;

FIG. 18 a is a schematic diagram of a charger for an audio deviceaccording to another embodiment of the invention, wherein the voice coilof a speaker is wired to the power cell of the audio device and isinductively couplable to a primary inductor;

FIG. 18 b is a block diagram showing the main elements of a switchingunit for connecting the charger of FIG. 18 a to an audio device;

FIG. 19 a is a schematic diagram of another embodiment of the chargerfor an audio device wherein an induction loop is incorporated into aneck support of the earphone unit;

FIG. 19 b is a schematic diagram of still another embodiment of thecharger for an audio device wherein an induction loop is formed byconnecting contact-terminals incorporated into the earphone cables;

FIG. 19 c is a schematic representation of an embodiment of the chargerfor an audio device wherein an inductive core extends through aninternal secondary coil and into the earphone unit for coupling with anexternal primary inductor;

FIG. 20 is a flowchart showing a possible method for charging theinternal power cell of an audio device;

FIGS. 21 a and 21 b are block diagrams schematically representing aninductive charger according a further embodiment of the invention incharging and driving modes respectively;

FIG. 22 a is a schematic representation of another embodiment of theinductive charger being charged by a primary coil;

FIG. 22 b is a schematic representation of the inductive charger of FIG.22 a being used to charge a mobile telephone wired to a secondary coil;

FIG. 23 a is a schematic representation of a mobile computer beingpowered by a primary coil via an integral inductive coil according toanother embodiment of the invention, and

FIG. 23 b is a schematic representation of a mobile telephone beingcharged by the inductive coil of FIG. 23 a.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

As required, detailed embodiments of the present invention are disclosedherein; however, it is to be understood that the disclosed embodimentsare merely exemplary of the invention that may be embodied in variousand alternative forms. The figures are not necessarily to scale; somefeatures may be exaggerated or minimized to show details of particularcomponents. Therefore, specific structural and functional detailsdisclosed herein are not to be interpreted as limiting, but merely as arepresentative basis for teaching one skilled in the art to variouslyemploy the present invention.

Reference is now made to FIG. 1, showing a power providing means 10 fora portable computer 12 consisting of a secondary inductor 14 wired tothe portable computer by a connecting wire 15 that is typically a twostripe multi-fiber insulated wire, such as used for providing power toportable computers via a transformer.

The secondary inductor 14 is essentially a coil which can be broughtinto proximity with a primary inductor 16 which is essentially anothercoil hardwired to a mains power supply 18. The primary coil 16 andsecondary coil 14 thus form an inductive power couple 20, allowing powerto be provided to the portable computer 12. The primary coil 16 may besituated in the table top 18 of a conference table, for example. Bysupplying power inductively in this manner, trailing wires may beavoided, providing a neater, safer and more flexible work environment.

It will be appreciated that, although a system for providing power to aportable computer is described herein, the power providing means 10 mayalso be applicable to the provision of power to other electrical devicessuch as a desktop computer, handheld computer, vehicle mounted computeror the like. Power providing means 10 may also be used by other portablesystems such as hand-held DVD players, projectors, hand-heldtelevisions, digital picture frames or sound systems for example.

As shown in FIG. 2, in an embodiment of the invention, the secondarycoil 14 may be integral to the portable computer 12, being built intothe base thereof, under the keyboard. Positioning the computer 12 over aprimary coil 16 a in a work-surface 22, for example, enables power to beprovided thereto, without trailing wires. The power may be used torecharge the electrochemical power pack (battery) 24 or to power theportable computer 12.

As shown in FIG. 3, in another embodiment of the invention, thesecondary coil 14 a may be coupled to a portable computer 12 designedfor optional power provision in this manner, via a jack 26 that isplugged into a dedicated jack socket 28 designed for coupling thesecondary coil 14 a. The dedicated jack socket 28 is separate from thepower supply jack socket 30 supplied for coupling to a power supply (notshown) of the type consisting of a transformer for plugging into a powermains socket that is typically provided. The dedicated jack plug 26 andjack socket 28 may usefully be physically different from power supplyjack socket 30 and jack plug (not shown), to prevent misconnection.Similarly, the inductive and transformer sockets 28, 30 are preferablyappropriately labeled, perhaps with letters I and T for inductive andtransformer, to prevent confusion.

However, since the purpose of inductive coupling is to avoid and replacetransformer coupling, in preferred embodiments, the secondary coil 14 ais connected to the portable computer 12 via the power jack socket 30designed for coupling to a mains via a power supply of the transformertype. In this manner, existing portable computers may be retrofittedwith a secondary coil 14 a for inductive powering.

Power may alternatively be provided to the portable computer 12 viaconnecting points designed for coupling to a rechargeableelectrochemical power pack within the housing for the power pack.

The secondary coil 14 a may be provided as a sort of puck on a wire thatcan be positioned over an access point in a surface where a primary coil16 is provided.

Alternatively however, usefully, to provide a neat solution, toeliminate trailing wires, recoiling such wires and to make disconnectingsimpler, as shown in FIG. 4 the secondary coil 14 b is preferablyincorporated into an accessory that has additional functionality. Forexample, it may be built into the side of a carrying case 40 or skinprovided for carrying the portable computer 12. In one preferredembodiment as shown in FIG. 5 the secondary coil 14 c is built into thehandle 42 of a carrying case 44.

As shown in FIG. 6, in one embodiment, the secondary coil 14 d is builtinto the shoulder strap 46 of a carrying case 48 which being flexible,gives more flexibility to the user, in that the computer 12 can be leftin its case, and situated anywhere within a radius of about 80 cm from a“power-spot” where a primary coil 16 is situated.

With reference now to FIGS. 7 a and 7 b, a retrofittable carrying handle52 for a computer 12 is shown. The handle 52 is attached to the computerby straps 54 and incorporates a built-in inductive power coil 14 eelectrically coupled to the computer via a power plug 56 which plugsinto the power jack 30 of the computer 12.

While the computer 12 is being carried, the straps 54 surround andsupport the computer 12 as shown in FIG. 7 b. However, as shown in FIG.7 a, when the computer 12 is laid down and in use, the support straps 54are opened allowing the inductive power coil 14 e to be coupled to aprimary coil 16 situated anywhere within their radius.

Alternatively, with reference to FIG. 8, the inductive power coil 14 maybe concealed inside a fashion-tag 62 attached to the computer 12 forexample by a connecting chain 64 or the like. Thus, by aligning thefashion-tag 62 to a power spot, the computer may draw power from aprimary coil 16.

In a further embodiment, a retractable secondary inductive coilattachment 70 may be retrofitted to a portable computer 12, as shown inFIGS. 9 a and 9 b. The secondary inductive coil 14 f is held in a tongue74 mounted upon the base of the computer 12 and when the computer 12 isin use as shown in FIG. 9 a, the tongue 74 may be extended so that thesecondary coil 14 f may couple with a power spot 16 within its radius.

When the portable computer is stowed, as in FIG. 9 b, tongue 74 may beretracted. Preferably, the thickness of the secondary inductive coilattachment 70 is less than the height of the feet 13 of the computer 12so that the attachment 70 does not prevent the computer 12 lying flatalong a table top.

Referring now to FIG. 10, an inductive charger 100 is shown for chargingthe power cells of a mobile communication device 200 such as mobiletelephone, personal digital assistant (PDA), camera or the like, indeedmany mobile devices include all of these functions. The charger 100consists of a secondary coil 120 wired to the mobile communicationdevice 200 typically via a power jack socket 220 of by a connecting wire140—typically a two stripe multi-fiber insulating wire, such as used forelectrically connecting a power source to a mobile communication devicevia a transformer.

The secondary coil 120 can be brought into proximity with a primary coil10 hardwired to a mains power supply, to form an inductive power couple,allowing power to be provided to recharge the cells 240 (FIGS. 12 a and12 b) of the mobile communication device 200. The primary coil 10 may besituated in the table top 20 of a conference table, for example, therebyallowing a phone 200 to be recharged thereby. By inductively rechargingin this manner, trailing wires may be avoided or at least minimized. Thesecondary coil 120 may be provided for example as a sort of puck 122 ona wire that can be positioned over an access point in a surface where aprimary coil 10 is provided. Alternatively the secondary coil 120 may bebuilt into an accessory of the telephone 200.

Over the years, mobile telephones have become a fashion item and variousfashionable accessories are often sold for use therewith. Suchaccessories include for example, replacement phone skins, protectivecases, belt clips, small ornamental pendants, sometimes known as “mobiledanglers” and the like. Some such accessories are merely decorative,others perform secondary functions such as providing added protection tothe device, or more convenient ways to carry the device. The secondarycoil 120 of the current invention may be incorporated into any of these.

As shown in FIG. 11 a, according an embodiment of the invention thesecondary coil 120 may be built into the skin or casing 260 a, 260 b ofthe mobile communication device. Positioning the mobile communicationdevice over a primary coil 10, as shown in FIG. 11 b, at an access pointin a work-surface 20, for example, enables power to be provided to thecharger thereby charging the power cells 240 of the mobile communicationdevice 200 without trailing wires.

The charger may be connected directly to the terminals of the powercells. Alternatively the charger may be connected to the power cells viathe power jack socket 220 of the mobile communication device 200.

According to another embodiment, shown in FIG. 12 a, the secondary coil120 may be provided with an adhesive surface 122 so that the coil 120may be adhered directly onto the power cells 240 of a mobiletelecommunication device 200 in conductive contact with the terminals ofthe power cells. When power cells 240 are positioned such that thesecondary coil 120 forms as inductive couple with a primary coil 10 thecells 240 may be recharged. As shown in FIG. 12 b, it is noted that inthis embodiment, the cells 240 are recharged directly from the secondarycoil 120 so the cells 240 do not need to be connected to the device inorder for them to be charged.

Referring now to FIG. 13, in further embodiment, the secondary coil 120is wired to a hermaphrodite power connector 160 including both a maleplug 162 and a female socket 164. The male plug 162 of the hermaphroditepower connector 160 may be coupled to the power jack socket 220 of thedevice while still providing a female socket 164 for accommodating theplug 40 of a conventional conductive charger. With this embodiment, auser may select between charging the power cells 240 of the mobilecommunication device 200 using the inductive charger 100 or theconductive type charger. The selection may be facilitated by means of aswitch although, preferably, the power connector 160 is configuredautomatically to select the inductive charger whenever the secondarycoil 120 is inductively coupled to a primary coil 10 and to select theconductive power supply whenever the female socket 164 is conductivelycoupled to a power source.

Alternatively, in the embodiment shown in FIGS. 14 a-c, the secondarycoil 120 may be built into a protective or fashionable case 300 whichmay be fitted to a mobile communication device 200. The secondary coil120 is typically wired to a hermaphrodite power connector 160 within thecase 300 which is configured to couple with the power jack socket 220 ofthe mobile communication device.

A further embodiment is illustrated in FIG. 15 showing a mobilecommunication device 200 having a secondary coil concealed within afashionable tag 400, such as a so called “mobile dangler” or the like,which may be plugged directly into the power jack socket 220 withadditional mechanical support 420 optionally provided when necessary.The inductive charger 100 of the invention may thus be incorporatedwithin a fashion accessory for the mobile communication device. In asimilar manner, the secondary coil 120 may be concealed in otheraccessories of the mobile telecommunication device such as a belt clip,neck cord, hand strap or the like.

According to still another embodiment, with reference to FIG. 16, aninductive charger 700 has a data channel coupled to the data jack socket280 of the mobile communication device 200. A USB (Universal Serial Bus)cable 720 leading to a USB plug is wired to the inductive charger whichmay be connected to USB jack socket 820 of a computer 800, for example,thereby providing a data link between the mobile communication device200 and the computer 800.

The USB connector 740 may, in addition, draw power from the computer 800and may thus be used to provide power to charge the power cells 120 ofthe mobile communication device 200 directly. As described hereinabovewith reference to the hermaphrodite connector, the charger 700 may beconfigured to select automatically between charging the power cells 120from the USB connector 740 or the secondary coil 120 depending upon theavailability of power.

U.S. Pat. No. 7,180,265 to Nokia Corporation, titled “Charging Devicewith an Induction Coil” describes an inductive charging device forcharging portable electronic devices with small footprints. The chargerdescribed in '265 includes a battery; a first induction coil coupled tothe battery; and an induction core extending through the first inductioncoil. The induction core has a portion which extends in an outwarddirection from the charging device and is adapted to removably couplewith a second induction coil of a portable electronic device byextending into the second induction coil.

The charger described in '265 is essentially a charging hook upon whichelectronic devices may be suspended by support loops. The hook iscoupled to the first inductive coil and is adapted to charge up theelectronic devices via the secondary inductive coils which may beincorporated into the support loops. '265 claims to provide a convenientway to organize devices being charged. However, for some applicationsthe support strap itself is undesirable, and as discussed hereinabove,there is a general desire to limit the number of wires, straps andcables.

By way of example, referring now to FIG. 17, a block diagram showing themain elements of an inductive charger 1100 for charging the internalpower cells 1220 of an audio device 1200, according to an embodiment ofthe invention.

The charger 1100 includes a secondary inductor 1140 wired to the powercells 1220 of the audio device 1200 via a rectifier 1240. An inductiveelement 1180 is incorporated into the earphone unit 1120 for inductivelycoupling the secondary inductor 1140 to an external primary inductor1320.

The primary inductor 1320 is typically wired to a power supply 1300 viaa driving unit 1310. The driving unit 1310 provides the electronicsnecessary to drive the primary inductor 1320, such as a switching unitproviding a high frequency oscillating voltage supply, for example.

Charger 1100 is suitable for use with audio devices 1200 requiringearphones 1121 connected via earphone cables 1122 such as, telephones,media players, personal digital assistants (PDA), Walkman®s, portable CDplayers, portable DVD players, mobile communications devices and thelike.

It is a particular feature of this embodiment, that at least a part ofthe inductive charger 1100 is incorporated in the earphone unit 1120 ofthe audio device 1200. This represents an advantage over prior artdevices such as the system described in U.S. Pat. No. 7,164,255 to Hui,which disadvantageously requires a secondary winding to be incorporatedeither within the device itself or in a dedicated adaptor, whereas theinductive charger 1100 of the present invention is suitable for use incharging audio devices with small footprints. Furthermore, because theinductive charger 1100 of the present invention is incorporated into theearphone unit 1120, the dimensions of the audio device 1200 itself arenot compromised by the addition of peripheral elements such as thesupport strap described in U.S. Pat. No. 7,180,265 to Nokia Corporation,for example.

With reference to FIG. 18 a, a schematic diagram of a charger 2100 foran audio device 2200 according to another embodiment is shown. In thisembodiment, the earphone unit 2120 includes a moving coil speaker 2122incorporated within an earpiece 2124 which is connected via a signalline 2125 to a plug 2126 for coupling to the audio device 2200 via anearphone jack 2202. The voice coil 2140 of the moving coil speaker 2122is a transducer that receives electrical signals from the signal lines2125 and converts them to audio signals.

The voice coil 2140 is additionally configured to be couplable to anexternal primary inductor 2320 which may be housed within a dockingstation 2322. Thus the voice coil 2140 may serve as the secondaryinductor 1140 (FIG. 17) of the inductive charger 2100, providing powerto the audio device via the signal lines 2125. Alternatively, dedicatedpower lines within the earphone unit 2120 may provide a conductiveconnection between the voice coil 2140 and the internal power cell 220of the audio device 200 via a rectifier 1240 (FIG. 17).

FIG. 18 b is a block diagram of the main elements of a switching unit2270 for connecting the charger 2100 of FIG. 18 a to an audio device2200. The switching unit 2270 is provided to selectively connect thevoice coil 2140 to the audio device 2200. The switching unit 2270 may bea separate unit that is retrofittable both to the audio device 2200 andto the earphone unit 2120. Alternatively, the switching unit 2270 may beincorporated into either the audio device 2200 or the earphone unit2120.

The switching unit 2270 may connect the voice coil terminal C to eitheran audio signal input A or to a charger output B of a switching circuit2272. The audio signal input A receives an audio signal 2250 from anamplifier 2260 which is communicated to the voice coil 2140. The chargeroutput B is connected to the power cell 2220 via a rectifier 2240 andmay be used for charging the power cell 2220 when the voice coil 2140 iscoupled to primary inductor 2320.

Optionally the switching circuit 2272 may be controlled by a frequencydetector 2274 which is configured and operable to detect high frequencyvoltage fluctuations along the signal line. High frequency voltagefluctuations are indicative that the voice coil 2140 is coupled to anactive primary inductor 2320. Therefore, when such high frequencyfluctuations are detected, the switching circuit 2272 may be connectedto the charger output B for charging the power cell 2220.

FIGS. 19 a-c are schematic diagrams showing various embodiments ofcharger 3100, 4100, 5100 for an audio device 3200, 4200, 5200. Withreference to FIG. 19 a, the earphone unit 3120 includes a neck support3122. Within the neck support 3122 is an induction loop 3140 ofconductive wire 3142 that is wound into a coil and connected to theinternal power cell 1220 (FIG. 17) of the audio device 3200 via arectifier 1240 (FIG. 17). The inductive loop 3140 is configured toinductively couple with an external primary inductor 320. The audiodevice 3200 may be conveniently stored by suspending the neck support3122 from a hook 3322.

In preferred embodiments, the hook 3322 is fabricated from aferromagnetic material which extends through a primary coil 3320. Whenthe neck support 3122 is suspended from the hook 3322, the ferromagneticmaterial forms a common inductive core 3180 between the primary coil3320 and the inductive loop 3140 within the neck support 3122. Theprimary coil 3320 and inductive loop 3140 thus form an inductive couplesuch that power may be inductively transferred from the primary coil3320 to the inductive loop 3140, thereby charging the power cells 1220(FIG. 17) of the audio device 3200.

Optionally, the inductive couple may be improved by the inclusion of aferromagnetic element (not shown) and may be incorporated into the necksupport 3122 and configured so as to couple with the ferromagneticinductive core 3180 of the hook 3322 so as to complete a magneticcircuit.

Although the example of an inductive loop 3140 within a neck support3122 is described herein, it is noted that a secondary inductor may behoused in various other components of an earphone unit. For example asecondary induction coil may be housed in a dedicated unit within theearphone cable. Alternatively a secondary coil may be incorporated intoa microphone housing such as is commonly included in the earphone cableof a cellular telephone. Alternatively again a secondary coil may beincorporated into a cable stowage unit such as a spring loaded winder asis sometimes included with earphone units for convenient storage.

An alternative embodiment of the induction loop is schematicallyrepresented in FIG. 19 b, wherein a charger 4100 for an audio device4200 according to another embodiment of the current invention is shown.The earphone unit 4120 of this embodiment includes two earpieces 4122 a,4122 b, each connected to the audio device 4200 via its own earphonecable 4124 a, 4124 b. A bundle of induction wires 4140, embedded in theearphone cables 4124, is connected to the internal power cell 1220 (FIG.17) of the audio device 4200 via the rectifier 1240 (FIG. 17).Contact-terminals 4142 a and 4142 b at each end of the bundle ofinduction wires 4140, typically located near the earpieces 4122 a, 4122b, are configured to conductively couple the ends of the bundle ofinduction wires 4140 thereby forming an induction loop. The inductionloop may be coupled with an external primary coil (not shown) such thatpower may be inductively transferred from the primary coil to theinductive loop.

FIG. 19 c is a schematic representation of a charger 5100 for an audiodevice 5200 according to still another embodiment of the invention. Theaudio device 5200 incorporates an internal secondary coil 5140 connectedto the internal power cell 5220 via the rectifier 5240. An inductivecore 5180 extends through the internal secondary coil 5140 and into theearphone unit 5120 for coupling with a primary inductor 5320. Theprimary inductor may, for example, be incorporated into a hook (notshown) for suspending the audio device 5200.

FIG. 20 is a flowchart showing a method for inductively charging theinternal power cell of an audio device in accordance with one embodimentof the invention. The method comprises the steps of:

step (a) providing an inductive charger incorporated within the earphoneunit of the audio device, including a secondary inductor connected tothe power cell via a rectifier;

step (b) providing an external primary inductor connected to a powersource via a driver;

step (c) inductively coupling the secondary inductor of the charger tothe external primary inductor, and

step (d) providing a variable voltage to the primary inductor.

Reference is now made to FIGS. 21 a and 21 b which are block diagramsschematically representing the inductive charger 6100 for use withanother embodiment of the invention. The inductive charger 6100 consistsof an inductive coil 6120 and a chargeable power pack 6140 which can beconnected to each other via a charging circuit 6160 or alternatively viaa driving circuit 6180. It is a particular feature of the currentinvention that the inductive charger 6100 may be switched between twomodes: (a) a charging mode as shown in FIG. 21 a, and (b) a drivingmode, as shown in FIG. 21 b. A mode selector 6170 is used to selectbetween the two modes.

With particular reference to FIG. 21 a, representing the inductivecharger 6100 in charging mode, the inductive coil 6120 is coupled to anexternal primary inductive coil 6220 which is connected to a powersupply 6240 preferably via a driving unit 6260. The mode selector 6170is configured to connect the inductive coil 6120 to the power pack 6140via the charging circuit 6160.

In the charging mode, the external primary coil 6220 generates anoscillating magnetic field. The internal inductive coil 6120 is placedin the vicinity of the external primary coil 6220, thereby creating amagnetic flux linkage between the primary coil 6220 and the internalinductive coil 6120, by which power is transferred from the externalprimary coil 6220 to the internal inductive coil 6120. Typically, directcurrent is required for reversing the electrochemical reactions thatresult in power supply from the power packs and the charging circuit6160 rectifies the alternating current generated in the inductive coil6120 thereby allowing the power pack 6140 to be recharged.

Referring now to FIG. 21 b, representing the inductive charger 6100 indriving mode, where the inductive coil 6120 is inductively coupled to anexternal secondary inductive coil 6320 which is wired to an electricload 6340. The mode selector 6170 is configured to connect the inductivecoil 6120 to the power pack 6140 via the driving circuit 6180. In thedriving mode the power supply 6140 provides power to the driver circuit6180 which provides a varying electrical potential to drive theinductive coil 6120. The driver circuit 6180 typically includes a highfrequency switching unit intermittently connecting the power pack 6140to the inductive coil 6120. The varying electrical potential across theinductive coil 6120 produces an oscillating magnetic field. Therefore,an external secondary coil 6320 which is brought into the vicinity ofthe inductive charger 6100 may inductively couple with the inductivecoil 6120. An electric load 6340 wired to the secondary coil 6320 maythereby draw power from the power pack 6140.

Many examples of rechargeable power packs are known and may be suitablefor use with various embodiments of the inductive charger 6100. Examplesof rechargeable electrochemical cells include nickel-cadmium cells,nickel metal hydride cells, alkaline cells, flow batteries and the like.Other power storage devices such as lead alkali accumulators, capacitorsand supercapacitors may also be charged by the inductive charger 6100.

Reference is now made to FIGS. 22 a and 22 b showing an exemplaryinductive charger 7100 according to another embodiment of the invention.A housing 7110 contains an inductive coil 7120 which is wrapped around aferromagnetic core 7122 and is connected to an internal power pack 7140via a control box 7130. The control box 7130 contains driving circuitryfor the driving mode, charging circuitry for the charging mode and amode selector (not shown). In alternative embodiments (not shown),additional circuitry may be provided for charging the power pack 7140from the mains or other external power source, such as solar power orthe like, via a dedicated jack. A dedicated jack may also be providedfor conductively connecting with and the powering of an externalelectrical load.

FIG. 22 a shows the inductive charger 7100 being charged up by aninductive power outlet 7200 which consists of a primary coil 7220concealed behind a facing layer, such as Formica or wood veneer, of aplatform 7280 such as a desk-top, a kitchen work-top, a conference tableor a work bench for example. The primary coil 7220 is wired to a powersupply 7240 via a driving unit 7260 providing the electronics necessaryto drive the primary coil 7120. Driving electronics may include aswitching unit providing a high frequency oscillating voltage supply,for example.

As inductive power outlets 7200 become more widespread, it is consideredlikely that devices may be hardwired to secondary coils, to draw theirpower inductively therefrom. In particular, mobile phones, media playersand the like which are generally connected to external chargers viaconnecting wires may be provided with internal charging circuitry thatincludes a secondary coil for inductively coupling to inductive poweroutlet 7200.

FIG. 22 b shows a mobile phone 7300 which has an integral secondaryinductive coil 7320 connected to its internal power source 7340 via arectifier (not shown). The mobile phone 7300 may be charged by placingit over an inductive power outlet 7200 such as shown in FIG. 22 a,thereby inductively coupling the secondary coil 7320 of the device withthe primary coil of the outlet 7200.

Where no inductive power outlet 7200 is available, the mobile phone maybe charged by placing it on top of the inductive charger 7100, as shownin FIG. 7 b. With the inductive charger 7100 set to driving mode, themobile phones secondary coil 7320 inductively couples with the internalinductive coil 7120 of the inductive charger 7100 and draws powertherefrom.

According to another embodiment of the inductive charger, shown in FIGS.23 a and 23 b, the inductive charger 8100 is incorporated into a mobilecomputer 8000. The mobile computer 8000 has a built-in inductive coil8120 for powering the computer from an inductive power outlet 8200, asshown in FIG. 23 a. Once coupled to a primary coil 8220, the inductivecoil 8120 may power the computer and/or charge the internal power pack8140 of the mobile computer.

The inductive coil 8120 of the computer 8000 may additionally be used tocharge an external device such as a mobile phone 8300 with an in-builtsecondary coil 8320, as shown in FIG. 8 b. A similar use is already madeof computers 8000 to charge external devices such as media players,mobile phones, mice, Bluetooth devices and the like, generally usingdedicated cables and via standard ports, such as their USB (universalserial bus) ports. One advantage of this is that no such dedicatedcables are needed.

It is noted that, apart from the mobile computer 8000 described herein,inductive chargers may be incorporated into other hosts, such aselectric cars, generators, emergency lights or the like for chargingelectrical devices thereby.

The scope of the present invention is defined by the appended claims andincludes both combinations and sub combinations of the various featuresdescribed hereinabove as well as variations and modifications thereof,which would occur to persons skilled in the art upon reading theforegoing description.

In the claims, the word “comprise”, and variations thereof such as“comprises”, “comprising” and the like indicate that the componentslisted are included, but not generally to the exclusion of othercomponents.

While exemplary embodiments are described above, it is not intended thatthese embodiments describe all possible forms of the invention. Rather,the words used in the specification are words of description rather thanlimitation, and it is understood that various changes may be madewithout departing from the spirit and scope of the invention.Additionally, the features of various implementing embodiments may becombined to form further embodiments of the invention.

1. A power providing system for an electrical device, said systemcomprising an earphone unit selectively connectable to said electricaldevice via at least one connector, wherein said earphone unit comprises:a secondary inductor selectively inductively couplable to a primaryinductor to provide power to the electrical device via said connector.2. The power providing system of claim 1, said earphone unit comprisingat least one inductive element for inductively coupling said primaryinductor to said secondary inductor.
 3. The power providing system ofclaim 2, said inductive element comprising said secondary inductor. 4.The power providing system of claim 1, secondary inductor comprising avoice coil of at least one speaker of said earphone unit.
 5. The powerproviding system of claim 1, wherein said connector comprises aconducting wire and said secondary inductor comprises at least one loopof said conducting wire.
 6. The power providing system of claim 1wherein said secondary inductor comprises at least one loop of wire isincorporated into a support strap for supporting the electrical device.7. The power providing system of claim 1 wherein said connectorcomprises at least two conducting wires and said secondary inductorcomprises at least one loop formed by connecting said conducting wires.8. The power providing system of a claim 1 wherein said inductiveelement comprises a ferromagnetic core extending through said secondaryinductor and into said earphone unit for selectively coupling with saidprimary inductor.
 9. An electrical device comprising at least oneearphone jack configured to connect to at least one earphone unitconfigured to receive power inductively from a primary inductor, whereinsaid earphone jack is connected to a signal input for receiving audiosignals and to a charger output connected to a power cell via arectifier.
 10. The electrical device of claim 9 wherein said earphonejack is further connected to a switching unit configured to selectivelyconnect the earphone unit to one of said signal input or said chargeroutput.
 11. The electrical device of claim 9 wherein said earphone unitcomprises a voice coil operable to convert an electrical signal into anaudible output, and further operable to inductively couple with aprimary inductor to receive power, wherein said earphone jack isoperable to selectively provide said electrical signal to said voicecoil and to receive power from said voice coil.
 12. A method forcharging an internal power cell of an electrical device comprising thesteps of: providing a primary inductor connected to a power source via adriver; providing an earphone unit comprising a secondary inductor;connecting said earphone unit to the electrical device via an earphonejack of said electrical device; inductively coupling said secondaryinductor to said primary inductor, and providing a variable voltage tothe primary inductor.
 13. The method of claim 10 wherein said earphonejack is connected to a switching unit operable to selective connectableto an audio signal input or a charger output.